Abstract:
We establish a rigorous Riemann–Hilbert (RH) framework for the coupled modified Yajima–Oikawa system. Unlike conventional approaches that initiate spectral analysis with the spatial Lax operator, we employ its temporal counterpart to derive the requisite analytic spectral functions and thereby formulate the associated RH problem. We then obtain explicit multi-soliton solutions in the reflectionless case. Leveraging symbolic computations in Maple, we analyze the ensuing soliton dynamics and illustrate their interactions. Our RH methodology not only elucidates the intricate spectral features of the coupled modified Yajima–Oikawa system but also provides a systematic procedure for constructing its general $N$-soliton solutions.